I've upgraded to Windows 7 from Windows XP. Now the font size in putty ist extremely ambiguous: Fonts smaller than 9pt are clear typed unreadable, with 9pt the fonts are too big for my usecase, especially the line breaks.

Depending on your remote system, you might want to use a font like DejaVu Sans Mono, and also set your encoding to UTF-8. It makes using more customised terminals easier to use (e.g. Oh-my-zsh themes almost all use UTF-8 characters in the prompt)